A need has long existed for a lightweight, portable, sturdy, and easy to assemble shelter to protect airplanes and other winged aircraft or fragile vehicles from the elements while parked on a flight line or otherwise not in use while on the ground.
Airplanes are very expensive and complex vehicles that contain equally expensive and very sophisticated avionics and navigation systems. Other vehicles and equipment of similar value, such as expensive cars, are sheltered when not in use to protect them from the damaging effects of the sun and the elements. However, airplanes parked on a flight line, or otherwise parked on the ground while not in use, are exposed to the deteriorating effects of the sun, and the elements, leading to excessive deterioration of exterior surfaces as well as the seats, instrumentation, avionics and navigation equipment located in the interior cabin.
Unprotected from the elements, an airplane's exterior surfaces can be physically damaged in extreme weather conditions. Both the external surfaces of the aircraft and its internal support members can become subject to excessive corrosion. Undetected, the resulting corrosion could, in time, lead to catastrophic weakening or warping of the airfoil surfaces, making the airplane dangerous to operate, and possibly no longer airworthy. While these corrosive effects result from exposure to the elements over time, there are some weather conditions that can have an immediate damaging effect to an unprotected airplane, such as hail. A severe hail storm may last only a few minutes, but the hail's impact on an airplane's wings and control surfaces can be the same as that of a ball peen hammer being struck against the surfaces, creating multiple divots. These hail divots can make an airplane that was a few minutes earlier completely usable (and no longer capable of being licensed as airworthy), with required repairs being so extensive that the aircraft may have to be salvaged.
Absent extreme weather conditions, the cockpit seats and the interior headliner, instrumentation and sophisticated electrical navigation and radio equipment are subjected to extreme heat cause by the convective and conductive greenhouse heating effect of the sun. The sun, shining through the aircraft's Plexiglas windshield and windows, can create temperatures in excess of 140 degrees Fahrenheit within an hour of exposure. Prolonged exposure to such heat can render interior instrumentation and radios inoperative, resulting in the need for expensive repairs.
Some airports do not have any fixed hangars to protect the airplanes on the flight line from the elements, while other airports will have a limited number of hangars for airplane owners to lease or purchase. However, the number of airplanes at such airports will far outnumber the available hangers. Waiting lists for hangers to become available can be very long, taking many years for a hangar to become available. As a result, airplane owners and operators have relied upon the use of airplane covers that consist of simple plastic or canvas to protect their airplanes from the deteriorating effects of the sun and the elements. These covers are generally form fitting and are stretched over the wings and body of the airplane to aid in protecting the airplane's surfaces. However, a disadvantage of these conventional covers is that they come into contact with exterior surfaces of the aircraft, and the objects that are affixed to the exterior surface, such as dirt or other contaminants. This direct contact can lead to damage to the exterior surface, such as when dust or dirt is entrapped in the cover and wind causes the cover to flutter and rub on the aircraft surface. This can cause scratching and other damage to polished and/or painted surfaces, thereby exposing the surfaces to corrosion, as well as causing damage to external objects attached to the aircraft such as radio and navigation antennae, which can lead to unsafe operating conditions. In the event of a hail storm the direct contact of the cover with the exterior surface may also not protect the surface from the hail's impact damage.
To overcome the disadvantages of conventional airplane covers, some prior art has suggested the use of portable hangars that can be assembled and disassembled to allow for protection of the airplane while parked. An example of such a structure is taught by Bogart in U.S. Pat. No. 7,089,951, issued Aug. 15, 2006. In Bogart's design a rigid structural skeletal frame is anchored to the ground, and is used with a cantilever structure. The frame and cantilever structure provide connections and support for cables and material to cover and protect the airplane. However due to the anchoring requirements, it is not possible to carry this shelter within the airplane itself when it is parked away from its home airport. Similar type designs were also suggested by Bray in U.S. Pat. No. 4,557,284 and by Ross in U.S. Pat. No. 6,360,492. In Ross, while there were no permanent anchors for the base structure of the shelter, the structure itself was very large and when broken down for transport would require a truck to move it to a new location, thereby making it impossible to be placed inside the aircraft being sheltered and used at locations other than the aircrafts home airport.